MDA's Third Quarter 2007 Results Conference Call Alert

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, plans to release its Third Quarter 2007 financial results at 5:00 p.m. Eastern Time (2:00 p.m. Pacific Time) on Tuesday, October 30, 2007.

MDA will host an earnings conference call, featuring remarks by Daniel Friedmann, president and CEO and Anil Wirasekara, executive vice-president and CFO, followed by a Q&A session.

The call is scheduled to begin promptly at 5:30 p.m. Eastern Time (2:30 p.m. Pacific Time).

To participate, please call the conference line approximately five minutes prior to the commencement of the call:

In Canada or the United States: 1-888-575-8232
In Toronto: 416-406-6419

The conference call will also be Webcast live and then archived at: http://www.mdacorporation.com/investor/events.shtml

Telephone replay will be available until November 6, 2007 at the following numbers:

Toll free - International: 1-800-408-3053
In Toronto: 416-695-5800
Pass Code: 3238762

About MDA

MDA provides advanced information solutions that capture and process vast amounts of data, produce essential information, and improve the decision making and operational performance of business and government organizations worldwide.

Focused on markets and customers with strong repeat business potential, MDA delivers a broad spectrum of earth and space based information solutions, ranging from complex operational systems, to tailored information services, to electronic information products.

MDA employs more than 3,000 people in locations across the United States, the United Kingdom, and Canada. The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.

Related Websites:
www.mdacorporation.com

Forward-Looking Statements

This release contains forward-looking statements and information, which reflect the current view of MacDonald, Dettwiler and Associates Ltd. with respect to future events and financial performance. Any such forward-looking statements are subject to risks and uncertainties and MDA's actual results of operations could differ materially from historical results or current expectations. Additional information on these and other potential factors that could affect MDA's financial results are detailed in documents filed from time to time with the applicable Canadian securities regulatory authorities.

The Toronto Stock Exchange has neither approved nor disapproved the form or content of this release.